Given the AP 18, x, ... , -12, -14, determine the value of x.

What is the formula for the  $n^{th}$  term of the AP   $\frac{2}{3},\ 1,\ \frac{4}{3},\ ...$  

Given the AP 5, 8, 11, ... , which term has the value of 272?

The $n^{th}$  term of an AP is given by   $T_n=\ 2\ -3n$  , find the common difference.

The $10^{th}$ term  of the AP  y, y + 2, y + 4 , ... is 16, find the value of y.

The 7^th term of an AP is 3 times the 2^nd term, find a relation between a and d.

Which of the following are the formulae for finding the sum of the first n terms of an AP

How many terms of the AP 2, 7, 12, ... will add up to 156?

What is the least number of terms of the AP   $3,\ \frac{7}{2},\ 4,\ ...$  to be added to obtain a total greater than 40?

The sum of the first 11^th term of an AP is 120, and the sum of the first 12^th term is 132. Find the value of the 12^th term.

The first three terms of an AP are -2, -4, -6, .... Find the sum of the 25 terms after the 3^rd term.